How does a condensing economizer work?
The condensing economizer improves waste heat recovery by cooling the flue gas below its dew point, which is about 135°F for products of combustion of natural gas. The economizer reclaims both sensible heat from the flue gas and latent heat by condensing flue gas water vapor (see Table 1).
How does an economiser work?
In a boiler system, an economizer captures the heat of the flue gas and transfers it to the feed water. As the flue gas exits the boiler, it enters an economizer with finned tubes. The finned tubes absorb the heat and raises the temperature of the boiler feed water, lowering the needed energy input.
What is the purpose of using economiser in boiler?
A common application of economizers in steam power plants is to capture the waste heat from boiler stack gases (flue gas) and transfer it to the boiler feedwater. This raises the temperature of the boiler feedwater, lowering the needed energy input, in turn reducing the firing rates needed for the rated boiler output.
How can we increase efficiency of economizer?
8. Incorporate an Economizer. Another way to improve energy efficiency is to incorporate heat recovery into a boiler system. The right type of equipment for a boiler system depends upon several factors, including boiler type, fuel used, stack material and operating conditions.
What is economizer efficiency?
An economizer is a mechanical device used to reduce energy consumption. Economizers recycle energy produced within a system or leverage environmental temperature differences to achieve efficiency improvements.
How is economiser efficiency calculated?
ECONOMIZER HEATING SURFACE CALCULATION Ratio r = This is the ratio (t —to)/ (To — T ) between the rise in temperature of the water and the drop in temperature of the gases. It varies between 0.6 and 0.8; that is, the water temperature increases by 0.7° when the gases drop by 1°.
How do you make an air preheater?
5. The rotating-plate design (RAPH) consists of a central rotating-plate element installed within a casing that is divided into two (bi-sector type), three (tri-sector type) or four (quad-sector type) sectors containing seals around the element.
What is an economizer HVAC?
An economizer is a part of the outdoor system, most often mounted on the roof, of an HVAC system for commercial buildings. The economizer evaluates outside air temperature and even humidity levels. When the exterior air levels are appropriate, it uses the outside air to cool your building.
How do you calculate the percentage of air leakage in APH of any boiler?
For this 700-MW power plant firing bituminous coal, leakages are calculated by using information on static pressure differences between the PA, SA, and flue gas streams, assuming two-thirds of the leakage occurs at the hot end of the APH. The air to flue gas leakage is 12% (by weight).
What is boiler efficiency formula?
Direct efficiency In order to calculate boiler efficiency by this method, we divide the total energy output of a boiler by total energy input given to the boiler, multiplied by hundred. GCV= Gross calorific value of the fuel.
What is regenerative air preheater?
Regenerative type of air preheater:- Tri sector regenerative preheater is commonly used in power plant. this design permits a single heat exchanger to heat both primary air which dries and transports coal from coal mills to the furnace and also secondary air which is used at furnace for combustion .
What is APH boiler?
Air Preheaters (APH) is the Shell and tube type Heat Exchangers used for preheating the air which is fed to the boiler or furnaces/kilns for combustion of fuels. Air Pre heater’s primary objective is to extract the waste heat from the flue gases leaving the boiler.
How does air preheater improve boiler performance?
Air Preheaters For every degree that the incoming air is heated, that results in less energy required from the boiler. In other words, an air preheater saves energy by doing some of the heavy lifting done by the boiler in order to raise the incoming fluid to the appropriate temperature.
Which one is not a boiler accessories?
Which of the following is NOT a boiler accessory? Explanation: The correct answer is mud hole (or sight hole). Feed pump, steam trap, steam separator are all boiler accessories whereas a mud hole is a boiler mounting.
What is the full form of APH in boiler?
An air preheater is any device designed to heat air before another process (for example, combustion in a boiler With the primary objective of increasing the thermal efficiency of the process. They may be used alone or to replace a recuperative heat system or to replace a steam coil.
Which materials are used for superheater tubes?
The superheater & reheater tubes may be made of carbon-The superheater & reheater tubes may be made of carbon- molybdenum steel, chromium-molybdenum steel, or 18-8 chromium-molybdenum steel, chromium-molybdenum steel, or 18-8 chromium- nickel (stainless) steel. nickel (stainless) steel.
What is superheater function?
A superheater is a device used to convert saturated steam or wet steam into superheated steam or dry steam. Superheated steam is used in steam turbines for electricity generation, steam engines, and in processes such as steam reforming.
What are boiler accessories?
The following are the important accessories of the boiler are: Feed water pump Injector Pressure reducing valve Economiser Air pre heater Super heater Steam drier or separator Steam trap 1. Feed water pump: the feed water pump is used to feed water to the boiler.
Can boiler function without accessories?
It may be noted that a boiler cannot function safely without the mountings. The boiler accessories are the devices, which form an integral part of a boiler but are not mounted on it. They include superheater, economiser, feed pump etc.
What is the function of boiler accessories?
Boiler accessories are devices that are installed along the boiler and the surrounding area to increase the efficiency of the boiler. These are not an indispensable part of the boiler, and thus without installing these devices, the boiler operation can be completed at low efficiency.